1. Field
The present disclosure relates to an electricity storage module and an electrically powered vehicle.
2. Description of the Related Art
Generally, an electricity storage module that includes a storage cell group (battery module) in which a plurality of storage cells (battery cells) have been stacked is known. Because this electricity storage module is, for example, mounted in electrically powered vehicles, such as hybrid vehicles and electric vehicles (EVs), the output voltage of the electricity storage module is made high by stacking many storage cells.
In an electricity storage module, two end plates are disposed at two ends of the storage cells in the stacking direction of the storage cells and are fastened to two ladder frames that are disposed in the stacking direction along side surfaces the storage cells. This kind of technology employed in a battery module is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2012-256466.
Such a ladder frame is formed by pressing a metal plate and is provided with a plurality of slits for distribution of cooling air. An upper edge and a lower edge of each ladder frame are provided with an upper flange and a lower flange each of which is formed by bending a corresponding one of the upper and lower edges inwardly in a width direction. An upper surface of the lower flange is provided with plate springs that have a U-shaped sectional shape, corresponding to the individual storage cells.